Really like your suggestions.
If they would implement this you actually could call the person a loadmaster.

I personally don't like that the co-pilot and loadmaster almost can't do anything. I really like your idea. It also would be nice if the loadmaster actually could use slingload, because he has a perfect view.

You already said it: "manually".
That's the point.
For each loadout you have to export, alt+tab out of arma, paste the clipboard in the document and repeat this for all loadouts.
Other people have to copy the loadout then, alt+tab in the game, import the loadout and repeat everything.
If you have about 30 loadouts, that's kinda time intensive and annoying.
And if you change something, you have to do it again.